Selector



March 25, 1930. HELMERT ET AL 1,751.815

SELECTOR Filed Aug. 29, 1928 Fig.1 Q

Fi w t t .Jnventons= Robert Hetment and Benno Johannesson by a AttorneyPatented Mar. 25, 1930 "l" FFICE ROBERT HELMERT, OF BERLIN-LICHTERFELDE,AND BENNO JOHANNESSON, OF BER- LIN-TEMPELHOF, GERMANY, ASSIGNOR-S TO U.LORENZ AKTIENGESELLSCHAFT, OF

BERLIN-TEMPELHOF, GERMANY SELECTOR Application filed August 29, 1928,Serial No.

The invention relates to switches or selectors suitable, for example,for automatic telephone and remote control systems, of the type that areprovided with several sets of brushes,

- which are movable in one direction only and capable of being operatedwith a continuous liding motion as well as a step-by-step moilOll. Theselection of one of the available sets of brushes is, in the presentcase, effected electrically by an auxiliary or brush selector.

According to the invention, the contact bank of the brush selector, inorder to avoid leading flexible conductors to each brush set, is rigidlyconnected to the brush sets of the bank contact groups, and the brushselector is set by the same driving mechanism as that which operates thebrush sets of the bank contact groups.

Constructional examples of the invention are diagrammaticallyrepresented in the accompanying drawings in which Fig. 1 represents aconnector in which the brush selector is directly operated by thedriving mechanism.

Fig. 1 shows a detail of construction.

Fig. 2 shows the circuit diagram therefor.

Fig. 8 shows additional arrangements for the group selectors.

Fig. 4 shows additional arrangements for so the line finders.

In Fig. 5 the principle of a brush selecting operation, by to and fromovements of the switch rod carrying the brush sets, is represented.

Referring to Figure 1, the brush sets 2, 3, 4, 5 and 6 wipe over thecontact bank 7 and are mounted, together with the contact bank 12 of thebrush selector, on the switch rod 1. The brush sets 26 are electricallyconnected with corresponding contacts of the contact bank 12 by means ofthe cable 48, whilst the brushes 13 of the brush selector are connectedby the flexible cable 16 to the distributor 17.

By means of the switch rod 1, the auxiliary selector brushes 30 areguided over the control contact bank 31, secured on the frame, in

order to effect switching operations in accordance with the position ofthe brush sets 26.

5 The driving mechanism consists of a con- 802,715, and in GermanySeptember 6, 1927.

tinuously rotating shaft 8 and an electromagnet friction coupling. Whenthe magnet winding 9 is energized, the armature 10 is driven by thewheel 11, secured to the rotating shaft 8. The brushes 13 are connectedto the armature 10 by the locking rod lt, which is guided in its slidingmotion by the bearings 15, 13 and 19 on the switch rod 1, so that thedriving mechanism acts directly on the brush s 13 of the brush selectorwhilst the brush sets are driven through the ratchet pawl 20, whichcouples the switch rod 1 with the locking rod l-i. The locking pawl 21is provided in order to prevent the setting memher from falling back.

The operations will first be described for a connector and withreference to Figs. 1 and 2. The numerical current impulses which serveto control th connector are caused by the earthing of the line a in thewell-known manner.

On sending a current impulse, the winding 22 of a control device isenergized through earth, a-line, winding 22, battery to earth (see Fig.2) The armature 23 is attracted and the contact set 24: changed over.The locking tooth 25 moves into a hole in the locking rod 14 whereby thelocking pawl 20 is pushed out. The electromagnetic friction coupling isenergized through the circuit shown in Fig. 2, (earth, contact 24,contact 26, winding 9, battery, earth) so that the locking rod 14:,together with the brushes 13, is raised, whilst switch rod 1, with thecontact bank 12, remains stationary. After the brushes 13 have moved astep on the contact bank 12, the locking pawls 20 and 21 fall into thenext hole of the locking rod 14, whilst locking tooth 25 of the controldevice returns to its upper stop 27, so that the brushes 13 are lockedin this position. During this operation, the projection 28 of thelocking tooth 25, on its rotation about the bolt 29, has caused thecontact 26 to open in order to break the circuit of the driving means.When the numerical impulse has ended, the armature 23 falls off so thatthe locking lever 25 returns into its normal position under the actionof the spring 32. On

the sending of the next numerical current impulse, the above describedoperations are repeated.

The slow-acting relay U is inserted at every current impulse by thecontact 24: and falls off, in a well-known manner, only when theseries'of current impulses has been completed (see Fig. 2). The couplingmeans is now en ergized'through earth, Contact u, position 0 of thecontrol contacts 31, brush 30, positions 1 -1( of thecont-act bank 12,brush 13, contact 26, magnet winding 9, battery, to earth. The lockingrot 1 1 and the switch rod 1 are then coupled together by the lockingpawl 20. When the brush 30 leaves the position 0 of the control contacts31, the circuit for the coupling means is opened so that the settingmember, held from falling by the locking pawl 21, remains stationary. Onthe second series of current impulses being sent, the same operationsare repeated as with the first series, with the difference that thelooking pawl is out of the range of operation of the locking tooth 25,so that locking rod 14 and switch 1 are moved together.

In the group selector ig. the brush selection is'eifected by numericalcurrent impulses as in the case of the connector, and no change is madein the operation of the brush selector but the movement of the brushsets over the bank contact groups takes place with uniform motion. Afterthe slow-acting re lay U has fallen on, the coupling is inserted as inthe case of the connector. The control device 31 is, however, in thiscase not interrupted between the positions 0 and 1 so that the settingmember is raised above position 1 until a testing operation on a freebank contact group takes place.

In order that the control device may also be used for locking thesetting member dur ing the testing operation, the lower stop 38 of thelocking tooth is constructed so as to be movable in accordance with Fig.3 and, in this particular example of construction, it is formed by aleaf spring. In the normal position of the switch rod 1, the stop 39presses the spring 38 down, so that the latter is located in a positioncorresponding to the stop in Fig. 1. When the switch rod 1 is raised,after the completion of the numerical selection, the spring 38 swingsout and presses the locking tooth 25 against the stop. 27. During thetesting operation, the Winding 9 is energized. The armature 28 isattracted so that the setting member is mo mentarily stopped by thelocking tooth 25 whilst the circuit of the coupling is opened by thecontact 26. (Figs. 1 and 2).

In the case of selectors with free selection over the contact bank 12and the contact bank 7 (for example, line finders according to Fig. 4:)the locking pawl 20, which in the normal position of the switch rod 1 ismoved out by a sloping member 10, falls into the locking rod 14. (instep 1, the circuit for the winding 22 (for example, by means of thecontrol contacts 31) is opened so that the armature 23 falls oil and thecircuit for operating the coupling is again closed through the contact26. The driving mechanism now moves the locking rod 14 and the switchrod 1 together. The locking tooth 25 rests, under theaction of thespring 4:1,on the stop 27. During the testing operation on a bankcontact, the winding 22 is energized, whereby. the setting mem-I her isheld as in the case of the groupselector.

A second constructional example for the setting of the brush selector isgiven in Fig. 5. The armature 16- of the electromagnetic frictioncoupling rests, in this case, on the switch rod 1. The setting ofthebrushes of the brush selector is efie'cted by to and fro movements ofthe switch rod 1. The brushes 13 of the brush selector are, in this casealso, mounted on the loclnng rod let which is guided on the switchrod 1. V

The nu nerical current impulses are received by the winding 22 of thecontrol device. l/Vhen the winding 22 is energized,

the armature 23 is attracted and thus inserts the electromagneticcoupling through the contact 24, whilst the locking tooth 25 which, inthis case does not engage in the lockin rod 1 1, is moved into theuppermost hole or the locking rod 1'? mounted on the switch rod 1. Thedriving mechanism now raises the switch rod 1 which moves the lockingrod 14, by means of the pawl a l, until the winding 9, as described inthe first constructional eX- ample, is disconnected by the opening ofthe contact 26. The locking rod '14 remains locked in the positionreached by the locking tooth 21, whilst the switch rod 1 falls back,since the locking pawl 411, on the first step, finds no locking tooth onthe rod 47. The locking tooth 25 remains locked since its book 46 hasengaged under the spring 15, thus keeping the contact 26 open. Only onthe completion of the numerical impulse, when the armature 28 againfalls off, is the hook 46 released by the spring 4:5 so that the contact26 is again closed by the return of the locking tooth 25.

Vfhen the first series of current impulses is finished, according to thefirst constructional example, the switch rod 1 is lifted,

without cooperation of the control device, by two steps so that thelocking pawl 11 no longer let the switch rod 1 fall back. The secondseries of current impulses then effects the step-by-step lifting of theswitch rod 1 together with the locking rod 14.

We claim 1. In a selector for automatic telephone and remote controlsystems, the combination with sets of field brushes and their contactbanks,

of a main brush selector carrying said field brushes, and an auxiliaryselector the contact bank of which 1s rigidly connected to and movablewith the field brushes and main brush selector.

2. In a selector for automatic telephone and remote control systems, thecombination with sets of field brushes and their contact banks, of amain brush selector carrying the field brushes, an auxiliary brushselector whose contact bank is rigidly connected to the main brushselector, and a common driving means for driving both selectors.

3. In a selector for automatic telephone and remote control systems, thecombination with field brushes and their contact banks, of relativelymovable main and auxiliary brush selectors, the latter having itscontact bank ri 'idly connected to and movable with the former, and adriving means for driving both selectors.

4. In a selector for automatic telephone and remote control systems, thecombination with field brushes, their contact banks, and a main brushselector, of an auxiliary brush selector whose contactbank is rigidlyconnected to the main selector, and operating means for actuating themain brush selector for a selecting action through the auxiliary brushselector.

5. In a selector for automatic telephone and remote control systems, thecombination with sets of field brushes and their contact banks. of amain brush selector carrying said field brushes, an auxiliary brushselector whose contact bank is rigidly connected to the said main brushselector, and a driving mechanism which directly drives the brushes ofthe auxiliary brush selector and is coupled to the main brush selectorafter the brush selecting operation is completed.

6. In a selector for automatic telephone and remote control systems, thecombination of a brush setting member, a brush selector whose contactbank is rigidly connected to the said member, a lifting rod carrying thebrushes of the brush selector, a driving mechanism which directly drivesthe lifting rod, and means for coupling the lifting rod to the brushsetting member a ter the brush selecting operation is completed and forthe purpose of selecting the individual contact.

7. In a selector for automatic telephone and remote control systems, thecombination of a brush setting member, a brush selector whose contactbank is rigidly connected to the said member, a driving mechanism whicheffects a to and fro movement of the setting member, and means wherebythe brushes of the brush selector are carried along with the settingmember in one direction of movement but are held in the oppositedirection of movement so that the said brushes are advanced withreference to their contact bank.

8. In a selector for automatic telephone and remote control systems, thecombination of a brush setting member, a brush selector whose contactbank is rigidly connected to the said member, a driving mechanism whicheffects a to and fro movement of the setting memher, an electromagneticlocking device which allows the brushes of the brush selector to movewith reference to the setting member, and a second locking device whichtakes over the locking when the brush setting member moves out of itsnormal position.

9. In a selector for automatic telephone and remote control systems, thecombination of a brush setting member, a brush selector whose contactbank is rigidly connected to the said member, a lifting rod guided bysaid brush setting member and carrying the brushes of the brushselector, a constantly rotating driving shaft, electromagnetic means forcoupling the said driving shaft to the said lifting rod, a magneticcontrol device whose armature controls the operation of saidelectromagnetic coupling means, means for coupling the lifting rod tothe brush setting member after the brush selecting operation iscompleted, and detents for preventing the falling of the liftind rod andthe setting member.

In testimony whereof we have affixed our signatures.

ROBERT HELMERT. BENNO JOHANNESSON.

